Various finger pricking devices or lancet assemblies have been commercialized for use by consumers, as well as for the use in hospitals, clinics and private practitioners, in order to take a small amount of blood as a sample. Such a device includes a lancet which has an element having a sharp part, namely a pricking element (such as a needle-like element), that is used to quickly prick the skin of a patient, or penetrate the skin and form an incision opening so as to allow a small amount of blood to bleed.
Such a lancet assembly is sterilized beforehand as to its distal end portion in its manufacturing process, because the pricking element forms the incision opening. The assembly must be protected from contamination by the ambient environment so as to maintain the sterilized condition until the assembly is put into use. It is also necessary to keep the pricking element from being exposed unnecessarily, lest the pricking element causes injury to human or object nearby when it is being handled.
With such considerations described above, a lancet assembly has been proposed which comprises a lancet structure wherein a distal end of the pricking element is sealed with a resin, and also a lancet holder has been proposed which is to be used in combination with the lancet structure (see International Patent Publication WO96/16599).
To use the lancet assembly described above, it is necessary to remove a resin cover, which seals the distal end of the pricking element, from the lancet structure inserted in the lancet holder, then hold the lancet holder while pressing, for example, a finger tip onto an opening positioned at a front end of the lancet holder, and apply a force toward the finger tip so as to push the lancet structure into the lancet holder, thereby to launch a lancet of the lancet structure.
It is inconvenient to hold the lancet assembly with fingers of one hand and remove the resin cover which seals the distal end of the pricking element with fingers of the other hand, for using the lancet assembly. It is desired to eliminate such action to remove the cover.
When the lancet is launched by using the lancet assembly described above, the user may be forced to have a period of mental preparation for the anticipation of experiencing a pain caused by a needle-like pricking element which penetrates the skin, the period lasting from the completion of preparation for launching the lancet to the time when the lancet is launched, thus causing nervousness depending on the user. It is desired to relieve such nervousness.